I have Vista installed on my work PC. Every so often when I'm on the net I lose access to some or all of the pages I need to look at. I know that Gordon has had the same thing happen since he mentioned it in one of his columns in PCW (you have at least one reader Gordon ).

Today I read a solution for the problem here. It involves opening a command prompt is admin mode and entering the command IPCONFIG /FLUSHDNS. Thought this might be of use to someone.

Good tip. Haven't seen the problem you describe here but then I tend to do most browsing from XP.

If it is a regular occurrence then, as you know, you can create a Desktop shortcut.

For those who aren't too familiar with this procedure, you right-click on the Desktop and select New and Shortcut. In the "location" edit box type "ipconfig" without the quotes and click Next. When prompted for the name you could type FlushDNS.

The shortcut is created on the Desktop but before you use it you must right-click on it and select Properties. Append " /flushdns" to the end of the Target text, which has been expanded to include the full path. Again no quotes and note the leading space. Then click on the Advanced button, select "Run as Administrator" and OK your way out. If you want to get fancy you can click Change Icon before finally OKing your way out of the Properties dialog box.

Hi guys, I'm afraid I'm still coming up with lots of addresses which don't resolve on my Vista system, but do resolve fine on other XP systems on the same network.

Strangely if you delete the www part, and just enter, say, http://cameralabs.com , then the page sometimes loads under Vista - but again not always. It seems to be completely random when this happens and what sites it happens with... very, very annoying!

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This is probably totally unrelated but are you, by any chance, using a Cisco firewall and/or router? There is an incompatibility between Vista and all but the latest releases of IOS (the software running the Cisco firewall). Memory tells me that the problem related to packet sizes. There is a temporary Vista workaround which worked for me until I managed to persuade Cisco to send me a free upgrade (and that was like squeezing blood from a stone).

If you think this might be part of the problem then let me know and I'll try and find my workaround tomorrow.

It's not this site per-se Darrin, but randomly ANY site. I'd say about 1 in 5 sites just don't load first time on my Vista systems, but the same sites do just fine on XP systems on the same network at the same time. But then later these sites WILL work fine on the Vista system - it seems random...

It describes how to temporarily turn off (and restore) the Receive Window Auto-Tuning feature so you can troubleshoot. This worked for me until I was able to upgrade my router's software. By the way, the Knowledge Base article describes opening a Command Prompt window to implement the fix but, to my surprise, it doesn't specify starting that Command Prompt window as an Administrator which would be my recommendation.

Just in case you think the Knowledge Base article doesn't describe your symptoms then check out the tech-recipes article which starts:

In Vista TCP Window Scaling is enabled by default. If your router does not tolerate this feature, it can cause random DNS and connection errors. This is a common cause of vista limited connection errors.

Anyway, it costs nothing to try the fix except a slight loss of TCP tuning and it is esy to put Vista back the way it was when you are done.